2B-CLDCLASS

Classifying cloud type is an important task for global cloud climatology studies. Different types of clouds are governed by different cloud dynamical processes and have different microphysical properties, which can result in quite different cloud radiative forcings. Because cloud type corresponds to specific cloud physical properties, cloud classification is also needed to apply other algorithms to derive quantitative cloud content and radiative data. 2B-CLDCLASS classifies clouds into either stratus (St), stratus (Sc), cumulus (Cu, including cumulus congestus), nimbostratus (Ns), altocumulus (Ac), altostratus (As), deep convective (cumulonimbus), or high (cirrus and cirrostratus) clouds, based on different rules for hydrometeor vertical and horizontal scales, the maximum Ze measured by the CPR, indications of precipitation, and ancillary data including ECMWF predicted temperature profiles and surface topography height.

Control Frame 0, CPR Calibration
16: CPR to point in 160 seconds
17: CPR 15º to the right
18: CPR 15º to the left
19: CPR 10º to the right -- default rotation
20: CPR 10º to the left -- default rotation
21: CPR 5º to the right
22: CPR 5º to the left
23 - 29: Target ID for testing - not planned for operational use
30 - 36: CPR rotation - not planned for operational use
37 - 39: Not planned for operational use

Control Frame 1, Four thruster closed-loop
40: Rotation into the OR orientation
41: Rotation into the x-track along the anti-ang momentum
42: Rotation into the x-track along ang momentum
43: Rotation into the orbit lower orientation
44: Rotation into alt. OR w/ CPR away from Sun
45 - 49: Not planned for operational use

Control Frame 2, One thruster open-loop
50: Rotation into the OR orientation
51: Rotation into the x-track along the anti-ang momentum
52: Rotation into the x-track along ang momentum
53: Rotation into the orbit lower orientation
54: Rotation into alt. OR w/ CPR away from Sun
55 - 59: Not planned for operational use

Control Frame 3, Two thruster open-loop
60: Rotation into the OR orientation
61: Rotation into the x-track along the anti-ang momentum
62: Rotation into the x-track along ang momentum
63: Rotation into the orbit lower orientation
64: Rotation into alt. OR w/ CPR away from Sun
65 - 69: Not planned for operational use

Control Frame 4, Four thruster open-loop
70: Rotation into the OR orientation
71: Rotation into the x-track along the anti-ang momentum
72: Rotation into the x-track along ang momentum
73: Rotation into the orbit lower orientation
74: Rotation into alt. OR w/ CPR away from Sun
75 - 80: Not planned for operational use

Control Frame 5
81: Body into the x-track along the anti-ang momentum
82 - 1023: Not planned for operational use

The pitch angle offset from nadir during normal operations. Pitch up is positive (radar points along the flight track in the direction of motion), down is negative (radar points along the flight track opposite the direction of motion).

Related News Articles

2016

CloudSat releases algorithm uncertainty study

September 1, 2016

The CloudSat algorithm development leads have completed a synthesis of algorithm uncertainties. The synopsis describes the known uncertainties in the Cloudsat algorithms and provides the relevant technical and peer reviewed references for data end-users. The algorithm development team plans to update the document periodically as new data releases become available.